When someone is excluded, someone else is often included. Despite this seemingly obvious insight, this form of social exclusion is underexplored. This dissertation investigates the ripple effect of social exclusion, how those who are included, rejected, and even outside observers can become roped into perpetuating exclusion, and strategies that mitigate its affective and cognitive consequences. Specifically, I document two ripple effects of exclusion in face-to-face interactions: the rejected tend to overestimate the included’s liking and preference for the excluder. At the same time, the included prefer to interact with the excluder. These two ripple effects create a self-fulfilling prophecy in which exclusion is both perceived and enacted. When the included receives social preferential treatment, they are motivated to reciprocate the excluder’s interest. Outside observers and even the rejected say that this is what the included should do. Yet this comes at a cost: the included is judged more negatively for interacting only with the excluder (rather than with everyone), and the rejected feels worse. When the included resists the pull of the rope, however, these consequences are mitigated. Finally, I examine seven social disconnection interventions involving friends and unknown peers, designed to either buffer by intervening before or promote recovery by intervening after the experience of social exclusion. I find support for the effectiveness of social disconnection interventions that involve actual (i.e., face-to-face) or symbolic (i.e., reminders) interactions with friends. Together, this dissertation illuminates how exclusion spreads and how its effects can be softened.